CVSTrac allows wiki pages to be deleted according to these rules:

*: The Setup user can delete any wiki page at any time.

*: Users with Delete privilege can delete wiki pages created by
   the anonymous user within the previous 24 hours.

*: Registered users (that is, users other than anonymous) can
   delete pages they themselves created within the previous 24
   hours.

When it is possible to delete a wiki page, a [Delete] hyperlink
appears in the uppper left corner of the screen.  Follow that
link to a confirmation page.

CVSTrac stores the complete text of every version of a wiki page
in its database.  If a single page has many edits, it can begin
to take up a lot of space in the database, especially if the page
is big.  Administrators may want to periodically go through and
delete all but the most recent two or three versions of large,
frequently edited pages.

All deletions are permanent.